Effect of Gibberellic Acid on Germination and Vigour of Kagzi Lime Seedlings

Abstract

Aims: To investigate the effect of storage treatments, gibberellic acid (GA3) and duration of soaking on seed germination and seedling growth in Kagzi lime. Study Design: The experiment was laid out in a Completely Randomized Design (CRD) with factorial concept and three repetitions. Place and Duration of Study: The experiment was conducted during July to November 2017 at Department of Fruit Science, Navsari Agricultural University, Navsari, Gujarat, India. Methodology: The experiment consisted of sixteen treatments which were repeated thrice. It comprised of three factors and their respective levels. Factor S1 indicated freshly extracted kagzi lime seeds and S2 comprised of seeds stored for 15 days. The different concentrations of gibberellic acid were G1 - 200 ppm; G2 - 300 ppm; G3 - 400 ppm and G4 - 500 ppm. Whereas, duration D1 stood for 12 hours and D2 for 24 hours. Results: The interaction between storage treatments, pre-sowing treatments and duration of soaking was found significant for all parameters included in the study except collar diameter and sturdiness quotient. Soaking freshly extracted Kagzi lime seeds in an aqueous solution of 500 ppm GA3 for 12 hours resulted in the minimum days for 50% germination (27.89), Seedling Vigour Index (3654.83) and survival percentage (84.70). The same treatment when extended for 24 hours recorded the highest germination percentage (95.68) and number of leaves (28.76). Soaking freshly extracted seeds in 400 ppm GA3 solution for 12 hours registered the maximum shoot length (21.63 cm). Kagzi lime seedlings raised from freshly extracted seeds resulted in higher collar diameter (2.04 mm) and sturdiness quotient (8.70). Further, a soaking duration of 12 hours proved better over 24 hours for collar diameter (2.04 mm) and sturdiness quotient (8.69). Between the different concentrations of GA3, 400 ppm gave better results for collar diameter (2.09 mm) and 200 ppm for sturdiness quotient (8.65).   Conclusion: Soaking freshly extracted kagzi lime seeds in an aqueous solution of 500 ppm GA3 for 12 hrs proved to be the best treatment combination for inducing early germination, higher Seedling Vigour Index and survival percentage. Nurserymen can employ these findings for early germination and vigorous seedlings in Kagzi lime.